Dual-tip marker



FIG. 1 is a left side elevation view of a dual-tip marker showing our new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a right side elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is an exploded right side elevation view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a top plan view thereof.

The broken line on the top in FIG. 7 is included for the purpose of illustrating environment and forms no part of the claimed design. 

The ornamental design for a dual-tip marker, as shown and described. 